The hip joint is a ball and socket joint and requires increased control, especially since it is the largest joint. It has many static and dynamic stabilisers, but also has the ability to propel and brake the body during running. Hip stabilisers will contribute to 4 times the body weight during running, where as glute max the main hip extensor absorbs 1.3 times bodyweight. When running at high speeds, up to 10 times body weight is produced by the hip flexors and hamstrings. 

The main muscles acting at the hip during sprinting are your hip extensors, which are involved in high speed acceleration. The gluteal muscles and hamstrings act in synergy with the calf complex, to help propel us forwards when we are running at full speed. The hip flexors contribute most during low speed jogging, carrying us forward in smaller strides. The outside/lateral hip abductors, gluteus medius and minimus, control pelvic stability.

As when we are running we are only ever in contact with the ground with one foot at a time, strength here provides pelvic stability during single leg stance. This prevents pelvic drop, a ‘Trendelenburg’ sign’, and knee valgus, when the knee collapses inwards, in straight line running. Testing hip strength to get a 1:1 ratio between your hip abductors and hip adductors (inner thigh, groin muscles) provides pelvic stability in running gait. When adding speed, change of direction and agility, hip abductors assist in side-stepping and cutting movements, creating that explosive movement with the calf complex to push us into a different direction. Specifically, gluteus medius strength prevents knee valgus, which in turn reduces the likelihood of serious knee ligament injury.